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Discussion Starter · #1 ·
Hi all, new to the group. I'm building a small block Chevy motor and in the market for a set of heads. 180cc, 64cc chamber, springs for hyd flat tappet cam.

There are so many options... AFR, Brodix, Edelbrock and a whole host of offshore stuff. I'm looking for some testimonies on what you've experienced to gain some good advice on choosing a set. I'm on somewhat of a budget but dont want to get burned either. I hear Jegs heads are built by Profiler and Summit built by Trick Flow. True?

Please let me know your thoughts. Thanks
 

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On a tight budget these are about the best deal you’ll find.

Straight plug trades a smidge of burn quality for way better header clearance. These are pretty much a Chinese copy of the Dart Pro 1, not as good as the real thing but easy enough to build a 400 plus horse 350 that is not radical at all, it will do that on a cam mild enough to run a stock stall converter and a high ratio interstate cruiser rear axle.

You need springs, valves, retainers, locks and stem seals to finish them out.

Shortest distance between these head’s in a box to on an engine is a Competition Products head improvement kit, there’s a bunch to choose from. Aftermarket aluminum heads typically use valve that has .1 inch longer stem as the casting thicknesses are greater and the ports relocated higher so the whole spring assembly is .1 inch higher compared to production Chevy head’s which drives the longer valve stem.


The next is aluminum head’s must have a steel spring base these are cups that locate the spring’s outside diameter (OD) or locators that locate on the spring‘s inside diameter (ID). Generally you’d use cups with nested springs and locators with single wound with or without a flat wound ID damper or with beehives. Here you’re positioning on the spring ID or OD diameter not the machined pad of the head which most likely is cut for racing diameter springs that are much bigger in OD often as much as 1.7 inch compared to production diameter of 1.25 give or take. Here once you have the head’s and chosen improvement kit you need to do some measuring of spring pad and guide OD and in tge case of locators shoulder height which is how much space at max is between the bottom edge of the installed stem seal to the spring perch of the locator. This stuff looks intimidating till you get in and play with it and we here will help you through this. Here are some links to examples:

Cups

Locators

For rocker arms you need to decide whether to go with push rod located or valve stem located these are the so called self-locating.
  • Push rod locating requires hex base screw in studs to hold a sheet metal push rod guide, these need to be the longer base screw of .73/.75 inch long. The often down side these have is when mixing aftermarket parts is alignment on the valve stem can go from wonky to needing corrective action which is usually cut and weld on the guide plate. These must use a hardened push rod, often only one end is hardened so you need to pay attention so the hardened end points up to the rocker.
  • Self aligning locate on the valve stem. In the case of aluminum heads they will use the same hex base rocker stud but these can be the shorter .5 inch base screw. Here any miss alignments are taken in the push rod angles, you need to check to be sure there is clearance for the push rod as it passes through the head casting, usually not a problem. These push rods do not need to be the hardened type though using three hardened type is not an issue if you do.

Aluminum prefers a composite head gasket which the thinnest is .024/.026 inch which added to the piston to deck clearance of .020/.025 inch gets you over the delightful .040 squish/quench clearance. However, with aluminum’s ability to move heat quickly for a street or street/strip engine this is of little consequence to detonation suppression. This is much more troublesome for iron head’s and their slower rate of heat transfer.

Rockers, in my opinion using 3/8ths studs and matching rockers is a waste of good money. 7/16ths doesn’t cost any more from your wallet while greatly stiffening the rocker/stud assembly which is less likely to loose control especially with self-guiding rockers if you happen to blow past 5500 revs some day.

OK that’s a ton to digest, talk to us before you order parts for guidance that nets more power for less money as you get ready for this project. Doing some of the brainiac work yourself saves a ton of money. Paying attention and doing some of the work can bring this in for around 500 maybe 600 dollars.

Bogie
 

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I used the Blueprint H8002K heads with Mahle .026 gaskets on my GM crate engine and it’s been working well for a couple of years. I bought them complete from Summit. They work well with about 16 degrees base timing and 18-20 mechanical advance. My vacuum advance adds about 15 degrees, and I don’t get any light throttle pinging.

You also need to look at how the new heads will work with your overall vehicle and engine setup. I used a Howard’s retrofit roller cam with 213/217 @ .050 duration because my truck weighs close to 5k with just two in the cab, and it’s not unusual to run at 8500+ lbs loaded. I have a TH350 with stock converter, but 4.10 gears and 31” tires maintain my low end “grunt”. You may have completely different requirements.
 

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when you build your engine (first choice) you pick the heads that will get you to the power level you want? Dont say the most possible for cheap,,,
be realistic and plan matching all the parts to make your goal. We can help but need you to say where you want to be?
 

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Discussion Starter · #7 ·
when you build your engine (first choice) you pick the heads that will get you to the power level you want? Dont say the most possible for cheap,,,
be realistic and plan matching all the parts to make your goal. We can help but need you to say where you want to be?
appreciate that... but my question was more about choosing a brand with regard to quality and reliability. Thanks
 
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